Fire-proof material for lining safes



@NrTED STATES PATENT Fierce.

NATHANIEL o. FOWLER, or BoSToN, MASSAOHUSETTS.

FIRE-PROOF MATERIAL FOR'LINING SAFES, DOORS, SHUTTERS, do.

SPECIFICATION forming part of--Letters Patent No. 231,662, dated August 31, 1880.

Application filed March 29, 1880. (No specimens.)

and preparation of a material to be used for the lining of safes and other places which it is desirable to fireproof, and which possesses important fire-proof qualities within a limited thickness.

It consists, preferably, of fibrous asbestos formed into a loose board or paper and saturated with magneso-calcite; but in case the fibrous asbestus is not readily to be obtained a board more porous and absorptive than blotting-board may bemade of slag-wool, or other non-combustible fiber, and similarly saturated with magneso-ealcite.

The safe or other place to be protected is fitted with this material put in in successive layers, either with or without air-chambers between the layers, as described in my former patent, and the interior layers may be of clay board placed between layers of the maguesocalcite board.

The manner in which these linings are made is as follows: I first make the magneso-calcite board by takinglfibrous asbestus or other fiber and forming it in a layer-say on the bottom of a sieve-which layer shall be anywhere from a sixty-fourth to a quarter of an inch thick.

This fibrous layer I completely saturate with a paste of slaked lime and magnesia, and allow it to compact and dry, so as to be pretty solid, either pressing it in forms or drying without pressure.

In lieu of the asbestus I may use slag-wool, and for other than outside layers vegetable fiber up to an amount of twenty-five per cent., more or less, of the finished compound. The slaked lime and magnesia (magneso-calcite) is preferably put upon the fiber in the form of a pulp; but if used dry it must be worked in by pressure. After the magneso calcite is put onto the fiber, either we't or dry, the whole is saturated with silicate of soda, so that the board becomes hard and firm. I then take the layers of this boardjand carefully fit them into the interior of the thing to be lined, and cement to them other layers of board, also care fully-fitted and jointed, either by silicate of soda or'by adhesion, between them by means of the magueso-calcite compound as a cement. I make the exterior layers entirely of fibrous magneso-calciteboard, as described; but for the intermediate layers, in lieu ofthe magnesocalcite board already described, clay board may be substituted in part, preferably in alternate layers, which clay board is also saturated with silicate of soda andwith a solution or cream of magneso-calcite applied as hot as is usual for just slaked lime to be, and cemented to the other board with silicate of soda or magneso-calcite cream.

The thickness desirable for the lining of a safe is from one to two inches. Such a thickness will resist heat equal to the melting of metal, requiring 2,800 to 3,000

Some of the intermediate layers of clay board may be advantageously saturated bya bath of sulphate of iron.

The lime and magnesia for making the magneso-calcite cream are in proportions of about two parts of lime to one of the magnesia, with suitable quantity of water.

The fiber for safelining should be about a quarter, by weight, of the finished board; but for some of the layers of paper-cases it will be advisable to have the board composed of a larger proportion of fiber-even as much as three-quarters may be used. This will make the sides of the cases stiffer.

Clay, if used, should be in the proportion of twenty-five to fifty oreven seventy-five per cent. of the whole weight of the board in which used.

. The sulphate-of-iron treatment is intended to give stiffness and firmness tothe board. The joints in the lining where the board is put in in successive layers should be madevery carefully and should be very close joints.

If desired to make a box of this composition without joints, it may be molded in a mold over a plunger or core under sufficient pressure, care being taken to distribute the fibrous binding material well through the mass.

This composition is applied to safes inside the metal lining, and to doors, shutters, blinds, &c., either upon one side only or between two surfaces. For paper-cases it may be made up into an independent box, or fitted as a lining to a tin or sheet-metal or other box, as desired.

Having thus fully described my invention, I claim and desire to secure by Letters Patent of the United States- The improved fire-proof composition of incombustible fiber and magneso-calcite, prepared and applied substantially as described. 10

NATHANIEL G. FOWLER.

Witnesses:

A. J. OETTINGER, F. F. RAYMOND, 2d. 

